Recently, radiation detection has become a pervasive concern for individuals, cities, governments, etc. In particular, since the attacks of Sep. 11, 2001, concerns about “dirty” or radiological-dispersal bombs have increased sharply. In response, many large-scale detectors have been installed at various locations in major metropolitan areas, ocean ports, airports, borders, etc. Radiation detectors have also been installed on top of and inside buildings. In addition, radioactive incidents such as the failing, imploding, or exploding of nuclear reactors can pose a serious risk of radiation leaks and exposure. The recent events in Fukushima, Japan are one example of such an incident.
First responders, including medical personnel, military personnel, and police and firefighters responding to radioactive incidents often require accurate information regarding radiation exposure. As an example, medical personnel need to know an individual's exposure level so that effective triage can be established. Other first responders require accurate information to plan for such tasks as rescue, evacuation, etc. As a result, personal radiation detectors which can record exposure to x-rays, gamma rays and beta rays are also used.
Common types of personal radiation detectors include ionization detectors, Geiger counters and thermoluminescent detectors (TLDs). Geiger counters and ionization detectors can record and display the dose rate (mRad/hr), as well as the integrated dose (Rads) in real time. TLDs are inexpensive but must be processed and read off-site after a period of time, typically one to three months.